What did you do in your shop today?

Started by MiniDave, September 23, 2018, 11:30:15 AM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

94touring

#875
The new motor already seems quieter.  Otherwise it's not a loud machine really. Figure the ac motor is spinning at 1775rpms and the pulley on the compressor pump is geared down to around 900rpms.  With the belts disconnected the ac motor makes zero noise.   Yours is probably 3250rpms?   

MiniDave

Yes, mine spins faster, no idea what RPM the pump is turning.......
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

jeff10049

Quote from: MiniDave on April 04, 2024, 07:24:21 PMYes, mine spins faster, no idea what RPM the pump is turning.......

Too fast LOL, At least that's how I feel about the new stuff I have usually put a smaller motor pully on my newer compressors. Quiets them down greatly and I've never had a noticeable reduction in cfm. I always time the cycle times on a new machine so I can judge how it's working when it gets some hours on it. When I had the business I bought two new recip compressors and immediately changed the motor pulleys. The cut-in to cut-out cycle time only increased by about 6 seconds but, the full load amps on the motor went from just over the motor FLA rating down to a 20% safety margin the motor and compressor temps came way down as well. After going through a motor a year per compressor I started putting the smaller pulleys on and my problems went away.

They push the new stuff hard so they can say its 16.4 cfm and the competitor's brand is only 16.2 then the competitor pushes harder for 17 cfm version. But what I've noticed is the duty cycle is getting less and less I don't even remember old compressors having a duty cycle. I'd rather slow it down and be able to run 100% duty cycle the 1 cfm less isn't near as bad as waiting 5 minutes out of every 10 for the thing to cool down.
Waiting is not even possible in a business and we were buying commercial units, not homeowner ones. I much prefer the older slower turning stuff like Dan has. Refurbing old compressors when you just need to get work done wasn't an option so we modified new ones. Unfortunately, most of the older stuff was also 3 phase which we didn't have so we bought the biggest rotary single phase we could a 10 horse I think it was and 3 recips basically had a whole 200 amp panel dedicated to air compressors. And it seemed like at least one of them was always broken down it got to the point where I had capacitors, contactors, pressure transducers, a motor, and a pump on the shelf. The only thing that never broke were the two harbor freight chiniseum refrigerated air dryers lol.

94touring

#878
That made me curious about the duty cycles on mine so I looked it up.  The AC motor is continuous duty.  The pump, which is a curtis E71, is continuous below 950rpms with intermittent operation at 1250rpms. I had it running quite a bit over the weekend, but I've never been able to use enough air for it to run continuously. 


MiniDave

But, do you know what RPM the pump turns?

I used to have a device that you could stick onto the end of the shaft and read RPM's, but I don't know where it got to.

I suppose if you know the motor RPM, and the sizes of the pulley's you could math it out......

I'll bet the paperwork that came with mine says it in there somewhere too......if I could find it! 
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

94touring

I have that rpm gun to verify. But as I recall it should be around 900rpms.  I'll verify next time I'm out there.

MiniDave

I'd like to know what mine is doing too - maybe I can take a page from Jeff's manual and slow mine down a bit too.
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

94touring

I know the pump pulley is roughly twice the diameter of the ac motor pulley, which would make sense for what I had read it would have come as new, around 900rpms. 

MiniDave

Now you're going to make me go measure it and do math - oh wait I can't, it's the eclipse!   :grin:
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

Red Riley

I've been putting some miles on the VTEC Elf, and I started to notice a weak return on the brake pedal, so decided to pick up a vacuum bleeder and do a fluid flush.
Can of worms, opened.
I guess the 9.5 inch racing discs on the front work pretty well, because I suspect the rear drums hadn't been doing anything in quite a while. I'm running a three master Wilwood pedal box, and the rear MC was completely inop and the whole rear brake circuit was bone dry except for a little thick sludge. Long story short, I bought two new Wilwood compact master cylinders, two 3/4 inch rear wheel cylinders, both rear hard lines, new master cylinder hard lines, and flushed and replaced the fluid. My first time doing double flared brake lines. I wish I had ponied up for the pro-level flaring tool, but I made do with the standard one with the bubble flare adapter. The vacuum bleeder did a great job, although it takes some getting used to. No brake fluid on the garage floor after a few days of driving around, so I guess I did okay.

MiniDave

So, now that you have everything cleaned out, does it feel any different when braking? Did you reset the balance bar so that the rears are actually doing some of the work?

PS I never noticed the mirror extension before, that's wild!
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

Red Riley

Quote from: MiniDave on April 16, 2024, 07:25:07 AMSo, now that you have everything cleaned out, does it feel any different when braking? Did you reset the balance bar so that the rears are actually doing some of the work?

PS I never noticed the mirror extension before, that's wild!
I haven't messed with the balance bar yet, I figured I'd drive it a bit to give everything a chance to settle in. The rear drums are actually working pretty well, though. I had my wife pump the brakes a few times while it was still on the jack stands after I bled everything, and it was locking up nice on the drums. It does feel different. There's a decent amount of pedal travel now, not engaging at the top of the pedal like it was doing.
Yes, those are original Desmo towing extensions. They actually make the wing mirrors functional. I can use them to back up the trailer.

MiniDave

I've only driven one or two cars with mirrors up on the wings like that and  I could not get used to them!
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

Brit_in_TX

Quote from: MiniDave on April 17, 2024, 08:07:20 AMI've only driven one or two cars with mirrors up on the wings like that and  I could not get used to them!

The Woody has mirrors on the wings, and they are basically useless!

94touring

I finally got around to changing the oil on the vespa. It was due for It's initial 700 mile break in oil change and had just turned 770. Wasn't too bad of a job, but it's rather difficult to catch the oil from the drain plug. I also swapped out the stock air filter for a higher flow foam filter.  That was a bit of a pain getting my hands to the little knobs to unscrew them.